Method and apparatus for non-invasive measurement of blood analytes with dynamic spectral calibration

Abstract

The present invention discloses a method and apparatus and method for achieving non-invasive measurement of analytes from human and animal blood through the skin using Raman lightwave technology. The apparatus includes a confocal signal collection system that effectively reduces the interferences from out-of-focus signals. The apparatus further includes a tissue permeation unit, which controls the amount of blood in the laser tissue interaction region. The change of aggregate spectra with time is used to construct a new series of differenced spectra, from which the spectral effects from surrounding static substances are calibrated out dynamically using the data processing method described.

1 - 18 . (canceled)  
     
     
         19 . An apparatus for non-invasively evaluating the constituents in the blood of a patient comprising: 
 a light source for generating a probe beam;    illumination optics for focusing the probe beam onto the target tissue;    a detector for measuring the optical response of the target tissue;    collection optics for collecting the optical response from the target and directing the collected optical response to the detector, said collection optics being arranged in a confocal manner.    
     
     
         20 . An apparatus as recited in the  claim 19 , wherein the collection optics includes focusing elements for creating an image of the target tissue in a plane, and further including a confocal hole located in the image plane, said collection optics minimizing the amount of out-of-focus light reaching the detector.  
     
     
         21 . An apparatus as recited in  claim 20 , wherein said light source is a narrowband laser and the collect optical response corresponds to Raman Spectroscopy.  
     
     
         22 . An apparatus as recited in  claim 21 , further including a means for varying the level of blood in the region of the target tissue so that measurements can be made at different blood levels.  
     
     
         23 . An apparatus as recited in  claim 19 , further including a processor for evaluating the constituents in the blood based on the optical response measured by the detector.